29 November, 2015

Rearing leafmines

Rearing leafmines is a great way to get up close with many elusive species of moth that are otherwise hard find and photograph as adults. Some leafminers are very low maintenance once taken into captivity whilst others can require a bit more care and attention in order to successfully breed through.

Phyllonorycter blancadella leafmine on Wild Service

Phyllonorycter blancardella larva feeding within the same mine

Over the autumn I collected a handful of Phyllonorycter leafmines containing larvae to attempt to rear into adult moths. Phyllonorycters feed, pupate and emerge from the small mines they create, making them an easy genus to rear. I simply place the leaf containing the leafmine into a sealed pot, label the species and/or plant it was found on and set it aside in a cool, dark place. Ideally most will emerge next spring, but there is always the chance of early emergences in warmer indoor temperatures.

Signed, sealed... 

Whether or not the end result will be a fully formed adult moth is another matter altogether. Many caterpillars will have been parasitised by another insect of some kind during their lifetime, and it's just a likely that a parasitic wasp will emerge from the leafmine.

This tiny wasp emerged from a Phyllonorycter coryli leafmine a couple of days ago - it would have hatched in the mine alongside the caterpillar, fed on it and eventually pupated in its own cocoon.

A parasitic wasp (possibly genus Pediobius) reared from a Phyllonorycter coryli leafmine

7 comments:

Dylan Wrathall said...

Bill, although it's not my thing - raising the adult moths from leaf mines has been something which Francis Solly has been doing for years, or so it seems. The results have seen some very important Kent/Thanet records - if that's possible? Because I have contact with Francis, I have been a beneficiary of many of these efforts and seen some exceptional moths as a result.
Modern digital imagery is able to assist us with being able to enjoy the remarkable detail of these superb little insects. Hoping all is well - Dylan

Steve Gale said...

I just might give this a go Bill!

Gibster said...

When I was in the throes of microlepping (10 odd years ago)I used to pop the mined leaf into a plastic cup - the type you get from a vending machine - pop some fine mesh over the top and hold it in place with an elastic band. Then whack it outdoors, somewhere sheltered like under a hedge. That way there's no worries about trying to keep the humidity levels right, or the temperature. The emerged adults (whether moth or wasp) almost always sit on the underside of the mesh, so it's easy to twang them into oblivion unless you take care removing the elastic band! Also worth remembering that some species leave the mine to pupate in soil, so gen up first in case a substrate is required. Best of luck :)

Bill Dykes said...

Dylan - They do look absolutely spectacular up close don't they! Huge admiration for the people who were doing leafmines before the internet made them more accessible - compared to Francis I've only just skimmed the surface! All's good with me thanks, hope you're well yourself!

Steve - Surprised you haven't already? Well worth a try!

Seth - Plastic cups would be a good idea - saves using up all my (very few) glass pots! Ah, I'll put them outside then - was a little hesitant in case the weather got too cold, but since they'd naturally pupate in exposed leaf litter I suppose they're made for it. Will report back on how I do in the spring. Cheers mate! :)

David Shenton said...
This comment has been removed by the author.
David Shenton said...

Bill,

Great to see you immersed into the world of miners and of rearing them through. Those images are very familiar.

If you haven't already done so, have a search for Brian Elliot's excellent article on rearing micro leps, it's on the Anglian Leps site.

I now go one step further, in a move somewhat akin to sneaking a look at your Christmas presents, in that I now study pupal morphology. This means that for many species, you don't even have to wait to rear through to confirm species, although I still do as the rewards of such fresh moths is well worth the effort. This even works with exuviae as the salient characteristics often remain after the imago has emerged.

All the best

Dave

Bill Dykes said...

Thanks Dave - seeing all your fantastic efforts on Flickr was one of the reasons why I decided to take leaf mines more seriously in the first place. I've been looking for literature on rearing them so will definitely check out that article you've suggested!

Examining pupal morphology sounds interesting - could be the incentive I need to finally invest in a microscope!

Cheers,

Bill